The field of the invention is generally that of indicators, and more specifically, to an improved miniature telltale module.
Most automotive instrument clusters contain fifteen to twentyfive warning or information indicators (telltales). Packaging these functions as part of an instrument cluster design inhibits the flexibility of the design and creates complexity throughout the assembly.
The instrument cluster housing typically provides the support for the telltale bulbs. The housing also incorporates complex structures to eliminate light leakage (or crosstalk) from adjacent telltales or into the instrument graphics areas.
Telltale bulbs are commonly powered through a flexible circuit which is placed on the back of the instrument case. The size and complexity of the flexible circuit required in each instrument is highly dependent on the telltale arrangement. Flexible circuits, therefore, add cost to the telltale function and increase the number of electrical connections thus decreasing the system reliability.
Current production instrument clusters contain a light bulb and socket for each telltale function. Material and assembly costs to install, test and inspect these bulbs accumulates into a significant portion of the instrument cluster cost because so many are needed. Incandescent bulb life and reliability continues to be an important factor even though bulb and socket design improvements have been made.